1. Technical Field
The present invention relates to an electronic apparatus and power management method thereof, and more particularly to an electronic apparatus and a method for conditionally power supplying.
2. Related Art
For an electronic apparatus used underwater, for example, the electronic apparatus conforming to the International Protection Code, has to equipped with a watertight case in which the seams of thereof are treated to make the case watertight. As such, when the electronic apparatus is operated underwater, the watertight case can securely enclose the electronic circuit to prevent water from entering the case. As for the waterproof requirement of buttons of the electronic apparatus, an impermeable film is adhered to the inner surface or the outer surface to cover the button holes of the case, so as to prevent water from entering the interior of the case through the button holes.
Please refer to FIG. 1, regarding to an external connection port 101a of the electronic apparatus, the external connection port 101a cannot be normally encapsulated in a watertight case 101 because it has to be connected with an external device. Generally, when the external connection port 101a is not connected with the external device, a waterproof cover 103a covers on the external connection port 101a. The waterproof cover 103a is combined with the case 101, so as to keep water away from the connecting terminals 105a of the external connection port 101a. As a result, neither short-circuit event nor electrolytic effect will occur to the connecting terminals 105a since they are kept away from water by the waterproof cover 101. Furthermore, the waterproof cover 103a also prevents water from entering the case through the external connection port 101a. 
Regarding to some types of the external connection port 101a for special requirement, an external connection port 101a of such types has to be always exposed on the case without the waterproof cover 103a. Although the external connection port 101a of such types waterproof, but the connecting terminals 105a thereof are still exposed to water. Furthermore, the external connection port 101a usually has at least one connecting terminals 105a that maintains a non-zero voltage level. Therefore, when being exposed to water, an electrolysis phenomenon occurs to and corrodes the connecting terminals 105a. And water also cause a short-circuit effect among the connecting terminals 105a and a signal malfunction.